pretty sure you can easily find one,, if I recall, the FP 20 venturi fits,, and is sized well for use

there is a lot of info about running this engine if you do a search.
they CAN be a bit finicky to run tending to run away a bit but it is managable
great match for a twister

Both RSM and Aero Products (Randy Smith) will have tongue mufflers for it. Randy also has very nice lightweight tube mufflers that will fit.

Isn't this one of the engines that really responds well to a low-pitch prop in a wet two-stroke, and just pukes or runs away if you try to run it like a Fox 35?

  Yes.

    Brett

The favored prop by many of the guys around here for this size of engine with Schnuerle porting is the ThunderTiger 11x4.5.  You'll also see the APC 11x4 and 11.5x4 recommended.  Some people like the APC 12.25 x 3.75 on the LA 46, but I don't know how it'll work on the FP.

A big bonus  for a FP 35 or fp 40 is the mounting holes are the same as a la 46, even the backplate, prop washer and Venturi are interchangeable.  La 46 is even lighter than the 40

Muffler, too?  I know they're the same between the FP20 and the LA25.

The Evolution 36 tongue muffler will also fit, and should be readily available for $14.99.

 Will, i just googled Huntersville NC, & you are 206 miles or just over 3 hrs away from me. I wont rule out visiting your flying site, but it will probably be when you are haveing an event there....Gene

The FP 20/25 venturi is probably the correct ID—Tower stock number LXCW99. The OS NVA is Tower stock number LXCR49. Both are straight drop-in.

Buy two venturis in case the stock FP 20/25 is too small. Push a 17/64" dia drill through an FP 20/25 venturi and you have the same size as the small venturi that used to come with the FP 35 and 40 when they were first released.

The APC 12.25 x 3.75 prop is probably too much for the FP 40—as noted, it's very good on the LA 46—some of my friends have cut it down to 11.5" dia and used it successfully on the FP 40. The other recommended props are worth trying as well.

Kaz Minato has them both.

http://www.shop-online.jp/mnti/index.php?body=list&category_id=91189&PHPSESSID=01e95d8b087d123c7d0d4d92f2736f27

Jay

Will, i just googled Huntersville NC, & you are 206 miles or just over 3 hrs away from me. I wont rule out visiting your flying site, but it will probably be when you are having an event there....Gene

Hey Gene, put Huntersville on your calendar for September 27th. It's 1/2A day, but everyone brings their big planes too, and there's plenty of room for everyone to fly. It's a fun group to hang out with.
Rusty

The E3030 standard muffler from the LA46 and LA40 will fit the FP40 and it isn't as restricted as the standard FP40 muffler. I know Geoff Goodworth suggests the FP 20 nva and venturi, but really they are a bit ion the small side for my liking. It does reduce the power output. I would use the standard FP40 venturi and NVA. Most props suggested will be near the mark, you need to select according to airframe size and weight. High rev, low pitch is the essential thing with these engines. A lot of people hate them, because of the frequent runaway situation that can result in trying to run them in the old fashioned way. Run properly they are good engines and don't deserve their evil reputation.

Andrew.

WHEW! lots to digest here. Rusty & Will, i marked my calender for the September event in Huntersville. I have a bunch of 1/2a stuff too.....Gene

Any time you feel a need to be overloaded with friendly advise, just ask a question here!

OK, I'll try again: FP-35, FP-40, LA40, and LA-46s all have the same exhaust outlet mounting hole spacing, therefore a muffler for one will fit all.

And the Tower 40, which came with a muffler that looks and works a lot like the E-3030, but is much lighter and (last I heard, I haven't personally checked) is still available from Tower.

Gene,

I have a couple of FP .40s with timing mods by Tom Dixon.  I run 0.27 inch venturi, 11x4.5 prop at about 9800 rpm on a Jamison Special, 10/22 fuel.  It's a very smooth running engine and does a great job on the Jamison.  It worked great at the Topeka, KS contest last weekend.  Tom's mods tamed the engine and made it much easier to use than the stock version.  If you run it stock you will probably want to run a 4 pitch prop.  Do not try to run it like a Fox .35 as it will likely runaway.

Jerry

Clint,

Some power is lost in re-timing, but 9800 rpm with a 11X4.5 prop & 10% nitro is way stronger than any Fox .35 on 15% nitro I have owned.  The FP puts out constant power with that set up, so I actually like the run characteristics better than the Fox.  Some may like the 4-2-4 & higher pitched props of the Fox better than the FP.  If you don't radically change the timing of the fp you can get a steady 2-2-2 run with a slight break and plenty of power using lower pitched props.  If you change the timing too much you will radically change the power output.  I know....I tried it.

Jerry

Start the flight in a wet 2, and before you know what happened it's leaned out and scorching through the pattern like the police are after it. 11x4 or 11x5 prop seems to keep it happy, but I suspect it's in a runaway condition.

This works for LA 46's, and (in my miniscule experience) with Tower 40's and the like.  It leaves stuff out, and I've never had an FP 40 to try it on.

Tach it before you launch.  If it runs away (yes, going to lean and "scorching through the pattern" is running away), then try launching it slower (by richening it up).  My biggest problem with just doing taching and tweaking is finding a needle setting where it'll stay in a good 2-stroke, without either staying slobbery rich for the whole flight, or going into runaway.  If you can't find a needle setting where it'll reliably stay at a good RPM, then try the following:

• More castor in the fuel (you should be running about 22 percent total oil, with at least 10% castor).
• A smaller venturi (or pile filters made of pantyhose over the venturi that you've got -- that works well, is adjustable, and filters are always good)
• Make sure the glow plug is hot, and in good condition

If it were my engine and that didn't work, my next step would be to ask here.

If it does work, then once you've established a baseline combination of fuel/prop/plug/venturi that works, play around with different props until you're really happy.

Do a search.  I can't remember for sure, but if I recall correctly the FP 40 is an OK stunt engine if run right (in a wet 2-stroke) but the 40 LA can be a real bear -- and even then, there are folks who are happy with the LA 40.  Someone will correct me if I'm wrong about the FP 40 being better than the LA 40.

So, having said that, how would one go about "retiming" this engine? Are we simply removing metal here and there, or does it require degree wheels, micrometers and machine shops and such?

Machine shops simply remove metal, precisely.

I've never retimed an engine.  The closest I've come is to build a new cylinder for a Cox 09 TD, which wore out about 15 seconds after it was broken in (next time I'll be more diligent about getting all the lapping compound off the parts!).  Some claim it can be "simply" done with a Dremel tool, and they may be right.  But whether you're filing on it by hand or using a milling machine to do it super-precisely, you have to know how to not damage the plating on the liner, and how to restore the piston-liner fit when you're done, or all you'll end up with is a horribly scored-up P&L that doesn't work worth a damn.

I am running a 40FP-S on my Sig Banshee. Got the engine new and put about an hour on it on the bench before going flying. It come with 2 venturis in the box. I settled for the small one. Running 20% Klotz castor 80% methanol and a hot Merlin plug. Prop is a Top Flite 11x5 wood. After much tweaking I have found this engines sweet spot. It wil not do a 4/2 break like a Fox. But is quite happy in a wet 2 on launch. Breaks nicely into a full 2 cycle in manoeuvres. Holds a wet 2 until about the last 45 seconds of the flight. I am currently using a Du-Bro 4oz rc tank converted to uniflow and mounted to a saddle with zip ties. Seems to work well although I will try a metal uniflow at some stage too.

Anyway Lees Machine shop sell venturis. I don't know what size to go for though. Anyone able to say what the dia of the small one for the FP-S is? As for NVA the OS one works fine, there are ST variants which work too.

Dan.